The metering of audio/video content (e.g., television programs, radio programs, etc.) is typically performed by collecting consumption records (e.g., viewing records) or other consumption information from a group of statistically selected households. Each of the statistically selected households typically has a data logging and processing unit commonly referred to as a home unit or site unit. The site unit may communicate with a variety of attachments that provide inputs to the site unit or that receive outputs from the site unit. For example, in the case where consumption consists of viewing conventional analog television broadcasts, a source identification unit such as a frequency detector attachment, which is a well-known device, may be in communication with a television to sense a local oscillator frequency of the television tuner. In this manner, the frequency detector attachment may be used to determine if the television is operating (i.e., is turned on) and to determine the broadcast channel to which the television is currently tuned based on a detected frequency. Additionally, a people counter, which is also a well-known device, may be located in the viewing space of the television and in communication with the site unit, thereby enabling the site unit to detect the number of persons currently viewing programs displayed on the television.
The site unit usually processes inputs (e.g., channel tuning information, number of viewers, etc.) from the attachments to produce consumption records. Consumption records may be generated on a periodic basis (i.e., at fixed time intervals) or may be generated in response to a change in an input such as, for example, a change in the number of the persons viewing the television, a change in the audio/video tuning information (i.e., a channel change), etc. In the case where the content consumed is associated with a broadcast television program, the consumption records may contain information such as a broadcast station or a channel number and a time (e.g., date and time of day) at which the audio/video content associated with the program was consumed. In the case where the audio/video content consumed is associated with a local audio/video content delivery system or device such as, for example, a personal video recorder (PVR), a digital versatile disk (DVD) player, a digital video recorder (DVR), a video cassette recorder (VCR), a set-top box (STB), game consoles, and/or any other device capable of reproducing audio and/or video information, the consumption records may include content identification (i.e., program identification) information as well as information relating to the time and manner in which the associated content was consumed. Of course, consumption records may contain other or additional information such as the number of viewers present at the consumption (e.g., viewing) time.
The site unit collects a quantity of consumption records and transmits collected consumption records, usually daily, to a central office or central data processing facility for further processing or analysis. The central data processing facility receives consumption records from site units located in some or all of the statistically selected households and analyzes the consumption records to ascertain the consumption behaviors of a particular household or a particular group of households selected from all participating households. Additionally, the central data processing facility may generate audio/video content consumption behavior statistics and other parameters indicative of consumption behavior associated with some or all of the participating households.
The rapid development and deployment of a wide variety of audio/video content delivery and distribution system technology platforms has complicated the task of obtaining and providing consumption records or information to the data collection facility. For instance, while the above-mentioned frequency detector device can be used to detect channel information at a site where television broadcasts are received via a radio frequency (RF) signal (because, under normal operating conditions, the local oscillator frequency corresponds to a known network channel that broadcasts a known lineup of television programs), such a device typically cannot be used with digital broadcast systems. In particular, digital broadcast systems (e.g., satellite-based digital television systems, digital cable systems, etc.) typically include a digital receiver or set-top box at each subscriber site. The digital receiver or set-top box demodulates a multi-program data stream, parses the multi-program data stream into individual audio and/or video data packets, and selectively processes those data packets to generate an audio/video signal for a selected portion of the audio/video content (e.g., a desired program). The audio and/or video output signals generated by the set-top box can typically be directly coupled to an audio/video input of a display and a set of associated speakers (e.g., a television system, a video monitor with corresponding speakers, etc.) As a result, the local oscillator frequency of the output device tuner (e.g., television), if any, does not necessarily have any meaningful relationship to the audio/video content (e.g., a broadcast channel, an audio and/or video program, etc.) being consumed within the household.
Similarly, obtaining consumption records or information is complicated in cases in which the audio/video content being consumed is delivered to the television via a local content source such as, for example, a PVR, a DVD player, a DVR, a VCR, a STB, a game console, and/or any other device capable of reproducing audio and/or video information at a consumption site. Such local audio/video content delivery devices or media sources enable the same audio/video content to be viewed at various times. Thus, the consumption of the audio/video content may be time shifted with respect to a time at which the audio/video content is originally broadcast and/or with respect to the different times at which the audio/video content is consumed at different consumption sites. The different times and manners in which audio/video content can be consumed across consumption sites precludes the use of a program lineup or the like at a central data processing facility to identify consumed audio/video content based on channel and consumption time information and significantly complicates audio/video content identification at the central facility. As a result, at least a portion of audio/video content consumption activities are not readily measurable using known media consumption measurement techniques.